A extension tube for 3DP's extruder, which helps users insert the filament more easily.
A small tube, which guides the position of the wires, makes it less likely to get stuck during manual refueling.

It is designed to fit a 0.4mm nozzle for 3D printing.
It may need to be sharpened with a rasp after printing.
I'm printing with a nozzle set to 0.4 (with a width of about 1.2mm; theoretically, you can also slice and print with 0.3), but after printing, I need to sand it down a bit to ensure that the filament can exit smoothly.